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Sudoku #24 — the solutions

The three Sudoku boards from October 24, 2026 — Easy, Medium and Hard — each with its solved grid and a path through it, step by step, that never needs a guess.

Easy — 36 digits given

Every cell falls to scanning: a digit with only one place left in a row, a column or a box.

The board

· 5 3 | · 6 · | 7 · ·
· · · | · 2 · | 6 · ·
· 2 6 | 7 5 · | 8 · ·
------+-------+------
· 6 · | · · 5 | 9 8 ·
· 8 4 | 9 · 2 | 3 6 ·
· 3 5 | 6 · · | · 2 ·
------+-------+------
· · 7 | · 3 8 | 4 9 ·
· · 2 | · 9 · | · · ·
· · 8 | · 7 · | 2 1 ·

The solution

1 5 3 | 8 6 9 | 7 4 2
8 7 9 | 4 2 3 | 6 5 1
4 2 6 | 7 5 1 | 8 3 9
------+-------+------
2 6 1 | 3 4 5 | 9 8 7
7 8 4 | 9 1 2 | 3 6 5
9 3 5 | 6 8 7 | 1 2 4
------+-------+------
5 1 7 | 2 3 8 | 4 9 6
3 4 2 | 1 9 6 | 5 7 8
6 9 8 | 5 7 4 | 2 1 3

A path through it

The order a solver takes — always the cheapest move left, so a pattern is only reached for when the singles run dry. 45 steps; yours need not match, and any order that never guesses ends on the same grid.

  1. Row 1, column 9 is 2. 2 has only one place left in the top-right box.
  2. Row 4, column 1 is 2. 2 has only one place left in the middle-left box.
  3. Row 6, column 1 is 9. 9 has only one place left in the middle-left box.
  4. Row 5, column 1 is 7. 7 has only one place left in the middle-left box.
  5. Row 2, column 2 is 7. 7 has only one place left in the top-left box.
  6. Row 2, column 3 is 9. 9 has only one place left in the top-left box.
  7. Row 3, column 9 is 9. 9 has only one place left in the top-right box.
  8. Row 1, column 6 is 9. 9 has only one place left in the top-center box.
  9. Row 2, column 9 is 1. 1 has only one place left in the top-right box.
  10. Row 2, column 8 is 5. 5 has only one place left in the top-right box.
  11. Row 3, column 8 is 3. 3 has only one place left in the top-right box.
  12. Row 1, column 8 is 4. 4 has only one place left in the top-right box.
  13. Row 4, column 3 is 1. 1 has only one place left in the middle-left box.
  14. Row 4, column 4 is 3. 3 has only one place left in the center box.
  15. Row 2, column 6 is 3. 3 has only one place left in the top-center box.
  16. Row 6, column 6 is 7. 7 has only one place left in the center box.
  17. Row 6, column 5 is 8. 8 has only one place left in the center box.
  18. Row 5, column 5 is 1. 1 has only one place left in the center box.
  19. Row 4, column 5 is 4. 4 has only one place left in the center box.
  20. Row 6, column 7 is 1. 1 has only one place left in the middle-right box.
  21. Row 6, column 9 is 4. 4 has only one place left in the middle-right box.
  22. Row 5, column 9 is 5. 5 has only one place left in the middle-right box.
  23. Row 4, column 9 is 7. 7 has only one place left in the middle-right box.
  24. Row 9, column 2 is 9. 9 has only one place left in the bottom-left box.
  25. Row 7, column 4 is 2. 2 has only one place left in the bottom-center box.
  26. Row 8, column 7 is 5. 5 has only one place left in the bottom-right box.
  27. Row 9, column 4 is 5. 5 has only one place left in the bottom-center box.
  28. Row 7, column 1 is 5. 5 has only one place left in the bottom-left box.
  29. Row 8, column 8 is 7. 7 has only one place left in the bottom-right box.
  30. Row 8, column 9 is 8. 8 has only one place left in the bottom-right box.
  31. Row 9, column 9 is 3. 3 has only one place left in the bottom-right box.
  32. Row 8, column 1 is 3. 3 has only one place left in the bottom-left box.
  33. Row 9, column 1 is 6. 6 has only one place left in the bottom-left box.
  34. Row 8, column 2 is 4. 4 has only one place left in the bottom-left box.
  35. Row 7, column 2 is 1. 1 has only one place left in the bottom-left box.
  36. Row 9, column 6 is 4. 4 has only one place left in the bottom-center box.
  37. Row 2, column 4 is 4. 4 has only one place left in the top-center box.
  38. Row 3, column 1 is 4. 4 has only one place left in the top-left box.
  39. Row 1, column 1 is 1. 1 has only one place left in the top-left box.
  40. Row 2, column 1 is 8. 8 has only one place left in the top-left box.
  41. Row 3, column 6 is 1. 1 has only one place left in the top-center box.
  42. Row 1, column 4 is 8. 8 has only one place left in the top-center box.
  43. Row 8, column 4 is 1. 1 has only one place left in the bottom-center box.
  44. Row 8, column 6 is 6. 6 has only one place left in the bottom-center box.
  45. Row 7, column 9 is 6. 6 has only one place left in the bottom-right box.

Medium — 29 digits given

Beyond singles, this board asks for a pointing line (3 times).

The board

· 9 · | · · 3 | 1 · 7
· · 8 | · · · | 4 · 5
· · · | 4 · · | 9 6 ·
------+-------+------
· · · | 3 · 2 | · 7 4
· · · | · 1 · | · · ·
2 5 · | 7 · 8 | · · ·
------+-------+------
· 3 4 | · · 1 | · · ·
9 · 1 | · · · | 7 · ·
5 · 7 | 6 · · | · 4 ·

The solution

4 9 5 | 2 6 3 | 1 8 7
3 6 8 | 1 9 7 | 4 2 5
1 7 2 | 4 8 5 | 9 6 3
------+-------+------
8 1 9 | 3 5 2 | 6 7 4
7 4 3 | 9 1 6 | 2 5 8
2 5 6 | 7 4 8 | 3 1 9
------+-------+------
6 3 4 | 8 7 1 | 5 9 2
9 8 1 | 5 2 4 | 7 3 6
5 2 7 | 6 3 9 | 8 4 1

A path through it

The order a solver takes — always the cheapest move left, so a pattern is only reached for when the singles run dry. 55 steps; yours need not match, and any order that never guesses ends on the same grid.

  1. Row 1, column 1 is 4. 4 has only one place left in the top-left box.
  2. Row 2, column 4 is 1. 1 has only one place left in the top-center box.
  3. Row 5, column 2 is 4. 4 has only one place left in the middle-left box.
  4. Row 5, column 1 is 7. 7 has only one place left in the middle-left box.
  5. Row 6, column 5 is 4. 4 has only one place left in the center box.
  6. Row 8, column 6 is 4. 4 has only one place left in the bottom-center box.
  7. Row 7, column 5 is 7. 7 has only one place left in the bottom-center box.
  8. Row 9, column 9 is 1. 1 has only one place left in the bottom-right box.
  9. Row 6, column 8 is 1. 1 has only one place left in the middle-right box.
  10. Row 9, column 6 is 9. Nothing but 9 is left for this cell.
  11. Row 2, column 5 is 9. 9 has only one place left in the top-center box.
  12. Row 5, column 4 is 9. 9 has only one place left in the center box.
  13. Row 6, column 9 is 9. 9 has only one place left in the middle-right box.
  14. Row 4, column 3 is 9. 9 has only one place left in the middle-left box.
  15. Row 7, column 8 is 9. 9 has only one place left in the bottom-right box.
  16. In the middle-left box, 3 can only sit in column 3, so it leaves the rest of that column.
  17. In the middle-left box, 8 can only sit in row 4, so it leaves the rest of that row.
  18. In the bottom-left box, 2 can only sit in column 2, so it leaves the rest of that column.
  19. Row 2, column 8 is 2. 2 has only one place left in row 2.
  20. Row 3, column 9 is 3. 3 has only one place left in the top-right box.
  21. Row 2, column 1 is 3. 3 has only one place left in the top-left box.
  22. Row 1, column 8 is 8. 8 has only one place left in the top-right box.
  23. Row 3, column 5 is 8. 8 has only one place left in the top-center box.
  24. Row 3, column 3 is 2. 2 has only one place left in row 3.
  25. Row 1, column 3 is 5. 5 has only one place left in the top-left box.
  26. Row 2, column 2 is 6. 6 has only one place left in the top-left box.
  27. Row 3, column 2 is 7. 7 has only one place left in the top-left box.
  28. Row 3, column 1 is 1. 1 has only one place left in the top-left box.
  29. Row 3, column 6 is 5. 5 has only one place left in the top-center box.
  30. Row 1, column 5 is 6. 6 has only one place left in the top-center box.
  31. Row 1, column 4 is 2. 2 has only one place left in the top-center box.
  32. Row 2, column 6 is 7. 7 has only one place left in the top-center box.
  33. Row 4, column 2 is 1. 1 has only one place left in the middle-left box.
  34. Row 4, column 1 is 8. 8 has only one place left in the middle-left box.
  35. Row 4, column 5 is 5. 5 has only one place left in the center box.
  36. Row 5, column 6 is 6. 6 has only one place left in the center box.
  37. Row 6, column 3 is 6. 6 has only one place left in the middle-left box.
  38. Row 5, column 3 is 3. 3 has only one place left in the middle-left box.
  39. Row 6, column 7 is 3. 3 has only one place left in the middle-right box.
  40. Row 4, column 7 is 6. 6 has only one place left in the middle-right box.
  41. Row 7, column 1 is 6. 6 has only one place left in the bottom-left box.
  42. Row 8, column 8 is 3. 3 has only one place left in the bottom-right box.
  43. Row 9, column 5 is 3. 3 has only one place left in the bottom-center box.
  44. Row 8, column 5 is 2. 2 has only one place left in the bottom-center box.
  45. Row 9, column 2 is 2. 2 has only one place left in the bottom-left box.
  46. Row 8, column 2 is 8. 8 has only one place left in the bottom-left box.
  47. Row 7, column 4 is 8. 8 has only one place left in the bottom-center box.
  48. Row 8, column 4 is 5. 5 has only one place left in the bottom-center box.
  49. Row 7, column 7 is 5. 5 has only one place left in the bottom-right box.
  50. Row 5, column 8 is 5. 5 has only one place left in the middle-right box.
  51. Row 7, column 9 is 2. 2 has only one place left in the bottom-right box.
  52. Row 5, column 7 is 2. 2 has only one place left in the middle-right box.
  53. Row 5, column 9 is 8. 8 has only one place left in the middle-right box.
  54. Row 8, column 9 is 6. 6 has only one place left in the bottom-right box.
  55. Row 9, column 7 is 8. 8 has only one place left in the bottom-right box.

Hard — 26 digits given

Beyond singles, this board asks for a pointing line (3 times), a claimed box and an XY-wing (2 times).

The board

· · 3 | · · · | · 7 2
6 · · | 5 7 · | · · ·
8 · · | · · 4 | · · ·
------+-------+------
· · · | · 3 7 | 4 · ·
· 7 · | 9 · 6 | · 8 ·
· · 9 | 4 8 · | · · ·
------+-------+------
· · · | 8 · · | · · 3
· · · | · 1 9 | · · 5
2 4 · | · · · | 9 · ·

The solution

4 5 3 | 6 9 1 | 8 7 2
6 2 1 | 5 7 8 | 3 9 4
8 9 7 | 3 2 4 | 1 5 6
------+-------+------
5 8 2 | 1 3 7 | 4 6 9
3 7 4 | 9 5 6 | 2 8 1
1 6 9 | 4 8 2 | 5 3 7
------+-------+------
9 1 6 | 8 4 5 | 7 2 3
7 3 8 | 2 1 9 | 6 4 5
2 4 5 | 7 6 3 | 9 1 8

A path through it

The order a solver takes — always the cheapest move left, so a pattern is only reached for when the singles run dry. 61 steps; yours need not match, and any order that never guesses ends on the same grid.

  1. Row 3, column 3 is 7. 7 has only one place left in the top-left box.
  2. Row 7, column 5 is 4. 4 has only one place left in the bottom-center box.
  3. Row 8, column 8 is 4. 4 has only one place left in the bottom-right box.
  4. Row 2, column 9 is 4. 4 has only one place left in the top-right box.
  5. Row 1, column 1 is 4. 4 has only one place left in the top-left box.
  6. Row 5, column 3 is 4. 4 has only one place left in the middle-left box.
  7. Row 7, column 1 is 9. 9 has only one place left in column 1.
  8. Row 8, column 1 is 7. 7 has only one place left in the bottom-left box.
  9. Row 8, column 2 is 3. 3 has only one place left in the bottom-left box.
  10. Row 9, column 4 is 7. 7 has only one place left in the bottom-center box.
  11. Row 9, column 6 is 3. 3 has only one place left in the bottom-center box.
  12. Row 3, column 4 is 3. 3 has only one place left in the top-center box.
  13. Row 7, column 7 is 7. 7 has only one place left in the bottom-right box.
  14. Row 6, column 9 is 7. 7 has only one place left in the middle-right box.
  15. Row 4, column 2 is 8. 8 has only one place left in column 2.
  16. Row 9, column 9 is 8. 8 has only one place left in column 9.
  17. Row 8, column 3 is 8. 8 has only one place left in the bottom-left box.
  18. Row 5, column 9 is 1. Nothing but 1 is left for this cell.
  19. In the top-left box, 5 can only sit in column 2, so it leaves the rest of that column.
  20. In the bottom-left box, 5 can only sit in column 3, so it leaves the rest of that column.
  21. In the bottom-right box, 1 can only sit in column 8, so it leaves the rest of that column.
  22. In column 1, 1 can only sit inside the middle-left box, so it leaves the rest of that box.
  23. XY-wing: one of its two wings must be 5, so no cell that sees both can be.
  24. Row 5, column 1 is 3. Nothing but 3 is left for this cell.
  25. XY-wing: one of its two wings must be 2, so no cell that sees both can be.
  26. Row 8, column 4 is 2. 2 has only one place left in column 4.
  27. Row 9, column 5 is 6. 6 has only one place left in the bottom-center box.
  28. Row 1, column 4 is 6. 6 has only one place left in the top-center box.
  29. Row 7, column 6 is 5. 5 has only one place left in the bottom-center box.
  30. Row 5, column 5 is 5. 5 has only one place left in the center box.
  31. Row 6, column 6 is 2. 2 has only one place left in the center box.
  32. Row 3, column 5 is 2. 2 has only one place left in the top-center box.
  33. Row 1, column 5 is 9. 9 has only one place left in the top-center box.
  34. Row 4, column 3 is 2. 2 has only one place left in the middle-left box.
  35. Row 2, column 2 is 2. 2 has only one place left in the top-left box.
  36. Row 3, column 2 is 9. 9 has only one place left in the top-left box.
  37. Row 1, column 2 is 5. 5 has only one place left in the top-left box.
  38. Row 2, column 3 is 1. 1 has only one place left in the top-left box.
  39. Row 1, column 6 is 1. 1 has only one place left in the top-center box.
  40. Row 2, column 6 is 8. 8 has only one place left in the top-center box.
  41. Row 3, column 7 is 1. 1 has only one place left in the top-right box.
  42. Row 3, column 8 is 5. 5 has only one place left in the top-right box.
  43. Row 3, column 9 is 6. 6 has only one place left in the top-right box.
  44. Row 1, column 7 is 8. 8 has only one place left in the top-right box.
  45. Row 2, column 8 is 9. 9 has only one place left in the top-right box.
  46. Row 2, column 7 is 3. 3 has only one place left in the top-right box.
  47. Row 6, column 2 is 6. 6 has only one place left in the middle-left box.
  48. Row 4, column 4 is 1. 1 has only one place left in the center box.
  49. Row 6, column 1 is 1. 1 has only one place left in the middle-left box.
  50. Row 4, column 1 is 5. 5 has only one place left in the middle-left box.
  51. Row 5, column 7 is 2. 2 has only one place left in the middle-right box.
  52. Row 6, column 8 is 3. 3 has only one place left in the middle-right box.
  53. Row 6, column 7 is 5. 5 has only one place left in the middle-right box.
  54. Row 4, column 8 is 6. 6 has only one place left in the middle-right box.
  55. Row 4, column 9 is 9. 9 has only one place left in the middle-right box.
  56. Row 7, column 2 is 1. 1 has only one place left in the bottom-left box.
  57. Row 9, column 3 is 5. 5 has only one place left in the bottom-left box.
  58. Row 7, column 3 is 6. 6 has only one place left in the bottom-left box.
  59. Row 9, column 8 is 1. 1 has only one place left in the bottom-right box.
  60. Row 7, column 8 is 2. 2 has only one place left in the bottom-right box.
  61. Row 8, column 7 is 6. 6 has only one place left in the bottom-right box.

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About Sudoku

Sudoku on Noggin is three boards a day, on the second shelf: every entry is checked at once, a hint fills the next cell a solver would and says why, and the first board finished is the day’s score, outside the daily line-up. How to play Sudoku, or play today’s.